1. Field of the Invention
The invention related to a printing device. More specifically, it relates to a printing device that allows the printing process to be continued without deteriorating printing quality or without halting the printing operation instantly even when a developing agent cartridge, whose service life has expired or which is not an authorized product, is used.
2. Description of Related Art
The toner cartridge of a printing device such as a printer is a consumable item and it is necessary to replace it with a new cartridge when the toner material stored inside the cartridge is used up. If the used up cartridge is replaced with a cartridge authorized by the manufacturer of said printer (“authorized product”), the printing quality and reliability are guaranteed. However, refilled cartridges that are manufactured by using used-up cartridge bodies of authorized products and refilling them with unauthorized toners or toners of other manufacturers (“refilled product”) or cartridges made by other manufacturers in imitation of authorized products (“unauthorized product”) are available on the market, and they sometimes caused deterioration of printing quality or reliability or even printer problems. Also, each component of the cartridge has a specific service life, so that even an authorized product is used, it may cause similar troubles when a service life of a part of its components has expired even if its toner has still remained.
In the meanwhile, there are printing device inventions that are capable of judging whether a cartridge is an authorized one depending on the data stored in the cartridge memory (e.g., JP-10-69139A), judging whether a cartridge is a refilled product by detecting increase of the toner quantity recorded on the cartridge memory (e.g., JP-2001-100530A), judging whether a cartridge is a refilled product by detecting damages on the cartridge body making the body impossible to open it without damaging a certain part of it (e.g., Patent Application 2001-125462), and others.
However, in any of these prior arts, it is designed to stop or prohibit printing if the loaded cartridge is found to be a refilled product and the like, so that it has a problem that a user can use a product by mistake without noticing that it is a refilled product, or an authorized product but its service life has expired, or an unauthorized product, in which case the user has no choice to stop printing if a replacement authorized product is not available on the spot.